The invention generally relates to covers over the openings of large containers, such as transfer trailers. The invention further relates to a control mechanism for opening and closing such covers.
Many different types of large containers are used for hauling loads and waste, such as solid waste, construction debris, landscape materials, recyclables, etc. One such type is a trailer designed for hauling by trucks, known as “transfer trailers”. Transfer trailers are typically rectangular-shaped with open tops and end doors. In a typical application, refuse is loaded into the container through the open top and the load conveyed to a dump or other discharge facility. The front of the trailer is disengaged from the hauling truck and tilted upward so that the refuse can be discharged through the open end doors.
Covers over the open tops are typically provided to prevent the load from spilling, sliding or being blown out the top of the container during transport. These covers have taken various forms in the past, including tarpaulin, lightweight nylon doors, open mesh plastic screens, etc. Some past trailer cover doors have consisted of two half-doors each rotating about a pivot point located adjacent each sidewall of the trailer. However, the doors may be 45 feet in length, and may each weigh 400 pounds, for example. Thus, the doors may be too heavy to manually open and close, and for this purpose power mechanisms have been employed. While flexible covers, such as mesh covers, are usually light enough for manual deployment, they are extremely cumbersome to maneuver and susceptible to accidental deployment due to wind gusts. Thus, separate power mechanisms are also beneficial for opening and closing flip tops of all kinds.
Known rotation control mechanisms for flip tops have disadvantages. They do not maintain control of the cover door(s) during their entire rotation. Thus, once a door has been rotated over-center, conventional powering mechanisms allow it to free fall down and possibly be damaged upon impact with the outer sidewall of the container. Another problem with prior flip tops having flexible covers is that the covers have a tendency to twist or flex during deployment and is susceptible to lifting off the container rim when the cover is supposed to be closed over the container.
One significant limitation of prior flip top cover systems is that they are generally limited to right hand or left hand action. In other words, the cover will pivot from only one side or the other of the transfer trailer. If it is desired to change the opening side of a prior flip top, it has been necessary to swap components of the cover deployment mechanism.
What is needed is a flip top cover system that eliminates the negative aspects of prior cover system designs. In particular, a flip top that avoids the flexing and lift off problems of prior systems is desired. Moreover, a cover system for a transfer trailer that can be readily changed between left and right hand deployment is needed in the art.